(a) Field of the Invention
This invention relates to a method for the utilization of the heat energy of sewage carried away through a sewer conduit.
(b) Prior Art
In every dwelling-house, hot water is consumed which is carried away as relatively hot sewage. For example, an energy amount on the order of 4000 kilowatt-hours may be wasted annually from an average one-family house by way of the sewage disposed of through the municipal sewer system. Much of this heat energy is lost through the air vent of the house's sewage system, it being common practice to provide a vent pipe opening to the atmosphere above the roof of the house for the ventilation of the sewage system of the house.
Heretofore, the heat energy from sewage from a dwelling-house has been used for the preheating of hot fresh water consumed in the same house. To this end, a heat exchanger was provided in the basement of the house and in this heat exchanger, the sewage and the cold fresh water are passed through separate conduit systems. However, the amounts of energy which can be recovered in this way from the sewage are seldom large enough to justify the costs for the installation and maintenance of the heat exchanger.